The role of magnetic flux in preventing scale on pipes has long been known, as evidenced by U.S. Pat. No. 438,579 dated Oct. 14, 1890, A. Faunce et al. Electromagnets for such purposes are represented by U.S. Pat. No. 531,183, Dec. 18, 1894, J. Harris; U.S. Pat. No. 2,652,925, Sep. 22, 1953, T. Vermeiren; and U.S. Pat. No. 4,151,090, Apr. 24, 1979 M. Brigante. Such systems are difficult to install and maintain, requiring electrical current connections and crating magnetic disturbances to sensitive electronic equipment in the vicinity.
Thus, permanent magnet configurations have been introduced such as set forth in U.S. Pat. No. 3,228,878, Jan. 11, 1966, D. Moody; and U.S. Pat. No. 4,367,143, Jan. 4, 1983, R. Carpenter. In these devices, longitudinally oriented magnets have a flux passing between north and south poles in narrow slice like flux paths that encompass only small portions of the cross section area inside the pipe, so that only portions of the passing fluid are subjected to the magnetic flux.
U.S. Pat. No. 4,605,498, Aug. 12, 1986, P. Kulish provides a magnet array encircling the pipe circumference and magnetized to present opposite poles radially from the outer pipe circumference to outer magnet circumference. This construction is quite ineffective and introduces significant problem in adaption to pipes already installed or those with limited accessibility. For example, a different model of magnet must be custom built for close fit for close fit with every different pipe size. With large pipe sizes of six inches (15 cm) or more in diameter such magnets are impractical, very large and very expensive. Furthermore, heavy flux concentrations necessary for proper fluid treatment are not feasible with this construction. The major flux path between north and south poles is thus directed in air outside the pipe and is ineffective in establishing a concentrated working flux within the fluid.
However, a significant problem occurs in converting flow within iron or steel pipes because magnetic fields tend to be shunted by the pipe walls before reaching the fluid flow region.
Accordingly, it is an objective of this invention to improve the art of permanent magnetic flux scale and corrosion control devices by introduction of magnetic structure able to penetrate the walls of iron and steel pipe and effectively treat fluid flow within the pipes.